An old joke involves tipping the waiter (the server) or the waiter (a person who waits). The joke has been cited in print since at least 1911:
 
Customer—Is it usual to tip the waiters here?
Waiter—Yes, sir.
Customer—Then hand over your tip. I’ve been waiting for you for nearly an hour.
 
 
Chronicling America
15 December 1911, The Bourbon News (Paris, KY), pg. 2, col. 4:
A Deserving Case.
Customer—Is it usual to tip the waiters here?
Waiter—Yes, sir.
Customer—Then hand over your tip. I’ve been waiting for you for nearly an hour.—Black and White.
 
15 August 1915, Miami (FL) Herald, sec. 2, pg. 11, col. 2:
THE ANTI-TIPPER.
The Washington Star relates that Dr. William Lynd Stevenson, president of the Anti-tipping League of Idaho, said at a league banquet in Boise:
 
“I visited New York last month. I put up at a fine hotel there—$4 a day, in fact, for room and bath. But what service!
 
“I went into the hotel restaurant the evening of my arrival to order dinenr. I ordered a simple enough dinner, according at least, to our Idaho standard—a dinner of clams, cold consomme, grilled brook trout, filet of beef with mushroom, chicken a la broche and so on—yet a simple enough Idaho dinner, but, by crinus they kept me waiting in the heat and noise and smells an unconscionable time. Unconscionable!
 
“Finally I called the maitre d’hotel and said:
 
“‘Is it the rule to tip the waiters here?’
 
“‘Yes, sir,’ said the man. ‘Oh, yes, sir.’
 
“‘Then,’ said I, ‘give me a good big tip. I’ve been waiting close on to three hours.’”
(Also in Chronicling America on August 16, 1915, and credited to the Boise Statesman.—ed.)
 
Google Books
October 1928, Boys’ Life, “Think and Grin” edited by Francis J. Rigney, pg. 48, col. 2:
Giving the Waiter a Tip
CUSTOMER: Are you supposed to tip the waiters here?
WAITER: Why, yes.
CUSTOMER: Then tip me, I’ve been waiting here for two hours.
   
Google Books
The Gigantic Joke Book
By Joseph Rosenbloom
New York, NY: Sterling Publishing Company, Inc.
1978
Pg. 175:
Customer: Are you supposed to tip the waiters here?
Waiter: Why, yes.
Customer: Then tip me, I’ve been waiting for two hours.
 
Google Books
Kids’ Nuttiest Jokes
By Mike Benny
New York, NY: Sterling Publishing Company, Inc.
2003
Pg. 71:
NAITER: Are you supposed to tip the waiters here?
WAITER: Yes.
NAITER: Good, because I’ve been waiting for twenty minutes.